Synthetic Sapphire vs. Calcium Fluoride
Synthetic sapphire belongs to the oxide-based engineering ceramics classification, while calcium fluoride belongs to the non-glass optical ceramics. There are 14 material properties with values for both materials. Properties with values for just one material (11, in this case) are not shown.
For each property being compared, the top bar is synthetic sapphire and the bottom bar is calcium fluoride.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 450 | |
| 80 |
| Knoop Hardness | 1860 | |
| 160 |
| Poisson's Ratio | 0.28 | |
| 0.26 |
| Shear Modulus, GPa | 150 | |
| 34 |
Thermal Properties
| Melting Onset (Solidus), °C | 2050 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 760 | |
| 860 |
| Thermal Conductivity, W/m-K | 30 | |
| 9.7 |
| Thermal Expansion, µm/m-K | 5.3 | |
| 19 |
Otherwise Unclassified Properties
| Density, g/cm3 | 4.0 | |
| 3.2 |
| Light Transmission Range, µm | 0.17 to 5.5 | |
| 0.15 to 9.0 |
| Refractive Index | 1.8 | |
| 1.4 |
Common Calculations
| Stiffness to Weight: Axial, points | 63 | |
| 14 |
| Stiffness to Weight: Bending, points | 64 | |
| 45 |
| Thermal Diffusivity, mm2/s | 9.9 | |
| 3.5 |